Dear Memrise,
You are not listening to the extensive feedback that has been provided multiple times:

a)
people want to use an app (not an untested “mobile website”)

b)
people want an offline mode (and are prepared to pay for it). Many users are in areas with poor internet coverage/ behind firewalls (e.g. the whole of China) or want to use the app on transport (planes/ trains/ subways etc.)

You need to escalate these the above 2 points to your CEO asap.

Either clone the existing app with all features and call it “Decks” and include an offline mode.